The present invention relates to fire-resistant face masks capable of capturing smoke particles, particulates and filtering gases. The fire-resistant masks extend the amount of time available for escape from a fire and/or smoke emergency situation and other emergency situations involving particulates and noxious gases and/or fumes.
Various types of apparatus are presently used to provide protection to escaping victims of fire, smoke, noxious fumes and similar emergency conditions. Prior escape masks include respiratory devices, surgical-type face masks and protective face and head gear.
Prior respiratory devices used by rescue squads include breathing filters, oxygen apparatus and respiratory-type masks having an air filtering unit. These respiratory devices are designed for multiple use and are consequently relatively complicated in construction and mechanical operation. In addition, they are expensive, cumbersome to store and have proven complicated for an untrained person to use under emergency conditions. The high cost of respiratory devices prohibit their availability on a wide spread basis for most buildings. This high cost makes it impractical for providing each building occupant with a respiratory device in case of a fire or smoke emergency. Furthermore, even if respiratory devices could be made readily available to building occupants, such equipment would have to be periodically checked and maintained to insure reliable operation when needed.
Recently, attempts have been made to develop respiratory devices which are less expensive and complicated in construction. For example, U.S. Pat. No. 2,845,927 to Hill, discloses a face mask frame which is fitted with a filter element. The filter element is a mat or pad of any suitable porous material. The pad may be made of cotton woven gauze or other fibers, or a felted mat of fibrous glass, natural or synthetic fiber or combinations of these materials. In addition, the pad can be made of terry cloth, natural or artificial sponge, foam latex or polyurethane foam. The filter element is not treated with any chemical compounds nor is the filter element moistened in any way. These masks have proved inadequate because, the filter element provides minimal protection from smoke and gas inhalation. The pad is both untreated and unmoistened, therefore, its filtering capabilities are only as good as its materials of construction.
U.S. Pat. No. 3,101,709 to Gruenewaelder, discloses a filtering element made of a foamed polyurethane sponge. A quaternary ammonium compound is added to the sponge for destroying macroorganisms and microorganisms, such as airborne bacteria. This mask protects the user from inhaling macroorganisms and microorganisms. Additionally, the mask is designed to destroy any macroorganisms and microorganisms that may be exhaled by the user. There is no indication that this mask would be effective in filtering smoke and gases generated during a smoke or fire emergency.
U.S. Pat. No. 3,664,335 to Boucher, et al., discloses a surgical face mask containing an antiseptic solution of quaternary compounds. The surgical face mask is soaked in the quaternary compounds prior to assembling the layers of the filter mat into a flexible porous pad. Amino acid sulphates such as Cytox may also be used as antiseptics. The masks are used to provide protection against contamination from airborne bacteria. There is no indication that this mask would be effective in filtering smoke and gases generated during a smoke or fire emergency.
U.S. Pat. No. 4,032,991 to Vandeweghe, discloses an envelope made of transparent fire-resistant sheet material having a portion enclosing a premoistened porous face mask. The face mask can be made of plies of woven fabric or other suitable porous material. The face mask portion is moistened with water or other liquid for trapping smoke particles and cooling the air passing into the nose and mouth of the wearer. In order to provide further smoke and noxious fume filtering capability, the mask may have granulated carbon particles or other filtering agents disposed between the fabric plies which make up the mask. These masks have proved undesirable due to shifting of the granulated carbon or other filtering agents disposed between the fabric plies. This shifting causes uneven and inadequate absorption of smoke particles.
U.S. Pat. No. 4,231,118 to Nakagawa, discloses a fire and smoke hood. The hood has a mouth piece portion in the front of the hood which is made of a poison absorbing agent. The poison absorbing agent can be activated carbon, zeolite, and Dowsonite. The poison absorbing agent is covered with or contained within an adiabatic non-woven fiber layer. The activated carbon, zeolite, and Dowsonite may be used separately or in combination in the mouth piece area. In addition, a carbon monoxide absorption agent may be used such as alumina hydrate which comprises Al.sub.2 O.sub.3, SiO.sub.2, NaO, Fe.sub.2 O.sub.3 and TiO.sub.2. Both the hood and the mouth piece are formed of non-flammable materials. The mouth piece absorbs smoke and poisonous gases. However, the absorption of smoke is uneven and inadequate due to shifting of the absorption material within the mouth piece.
U.S. Pat. No. 4,297,117 to Holter et al., discloses a fire-proof respiratory face mask made of two layers of a fleece-like or felted material reinforced with an adsorption material. The adsorption material consists of soda lime, active carbon dust, copper dust and/or manganese dioxide dust. The adsorption material is deposited on a base material made of expanded calcium-aluminum-silicate. The particles of the base material are surrounded with a layer of soda lime and a layer of active carbon, as well as a layer of copper dust soaked into a caustic soda solution and/or a layer of manganese dioxide dust. The ceramic fibers extend through the adsorption material and link the fleece-like materials together. The fleece-like material should be made of ceramic fibers. The ceramic fibers have good filter properties and a high heat insulating efficiency. Dust and drops of liquids will be retained in the filter because of the ceramic fibers filter properties. Noxious gases will be retained by the adsorption materials. The masks are complicated in their construction. The ceramic fibers must be situated in such a way that the layers of the mask are linked with each other through the layer of base material. If this is not accomplished the smoke absorbing material shifts, resulting in uneven filtering.
While there have been attempts to develop escape devices and masks which are effective in capturing smoke particles, particulate and filtering gases, these prior art devices often lack the efficiency necessary for practical and wide scale implementation. Typical problems encountered in using fire escape masks and devices include inadequate filtering of smoke particles, particulates and gases, complicated construction causing decreased utility in emergency situations, costly maintenance and testing for proper operation, inadequate fire-resistance of the materials of construction and shifting of the smoke absorption materials within the mask. Consequently, there is a need for alternative fire-resistant face masks for economically and uniformly capturing smoke particles, other particulates and filtering gases.
It is therefore an object of the present invention to provide a disposable one-use, low cost smoke escape face mask capable of capturing smoke particles and particulates and for filtering gases.
It is further an object of the present invention to provide a highly fire-resistant escape face mask for use in various forms, which extends the amount of time available for escaping from a fire and/or smoke emergency situation and other emergency situations involving particulate and noxious gases and/or fumes.